There are also agencies available that charge homeowners up to £50 a day for reference and diligence checks. They can also arrange for homeowners to pay their house-sitters a small fee of around £10 to £20 a day.

Personal finance commentator Jasmine Birtles says using an agency can have its advantages if something goes wrong.

"With an agency you have a central body. If you are a homeowner, you have someone to complain to," she says.

"If you are the house-sitter, you also have someone to complain to and they can adjudicate.

"If you have done it through a free website, it is ultimately up to you. I would recommend that both sides sign some form of contract."

She says there are also potential difficulties surrounding insurance, to cover any injury that a house-sitter might suffer in the house.

"It is a good idea to take out landlord's insurance, for example, as it is a public liability insurance," he says.

"It is also a good idea to mention to your insurance company that you have got someone staying in your home, but generally speaking the insurers are not too concerned about that because everybody has guests staying."

House-sitting is not for everyone. Looking after animals requires a lot of work, and not everyone has the flexibility to move around.

Kristie West says the unpredictable lifestyle suits her needs. But she says the only downside is saying goodbye to the pets she has been looking after.